A display device for achieving glasses-free 3D display comprises a liquid crystal display (LCD) panel and a shield such as a parallax barrier or an LC lens disposed in front of the display panel. In the display process, a plurality of fields of view are formed through the parallax barrier or the LC lens in front of the display panel, so that light emitted by different sub-pixel units on the display panel falls into different fields of view. Two eyes of a viewer are respectively located in different fields of view, receive different images, and produce 3D sense in the brain of the viewer.
The principle of the LC lens is to focus or diverge light beams by utilization of the birefringent characteristics of liquid crystal molecules and the characteristic of liquid crystal molecules of being arranged along with the variation of electric field distribution, and with control the arrangement direction of the liquid crystal molecules by voltage change, and an effective optical zoom effect can be achieved in a small space.
The LC lens includes a plurality of lens units that are parallel and adjacent to each other. Each lens unit has the function of diverging or focusing light from a left field of view and a right field of view of the display panel. Each lens unit corresponds to two adjacent columns of sub-pixel units on the display panel, one column of sub-pixel units are configured to display an image corresponding to the left field of view, and the other column of sub-pixel units are configured to display an image corresponding to the right field of view. In general, the LC lens comprises: a first substrate and a second substrate arranged opposite to each other, a liquid crystal layer disposed between the first substrate and the second substrate, and first electrodes and second electrodes disposed on the sides, close to the liquid crystal layer, of the first substrate and the second substrate respectively.